After 40 years with Judas Priest, KK Downing has quit the band. The English heavy metal group will complete their farewell tour without their co-founder, replacing him with Richie Faulkner, a guitarist half his age.

Downing's retirement is abrupt, and Judas Priest have not given a reason for his decision. His band is just over a month away from launching their last ever tour, which sees them trotting from Holland to Bournemouth to Mexico for most of the rest of 2011. "Having thought long and hard about how to proceed," the metal legends said in a press release, "[we] agreed [to] go ahead with the tour and not let the fans down all around the world."

While Downing leaves big solo slots to fill, the band claim to have found "the perfect replacement". Faulkner, 31, will allegedly "help set the stage on fire", although Google has not been helpful at establishing his guitar-god pedigree (he is known to have played in the backing band for Lauren Harris, daughter of Iron Maiden's Steve). Judas Priest still plan to release a new album next year, which will presumably include Downing's contributions.

Downing had been a member of Judas Priest since 1970. In a recent Q&A, he seemed satisfied with the band's legacy: "I feel that Priest has played its part in music history and feel very proud to have achieved what we have. So there is a good, positive feeling inside me and, of course, I feel very indebted to the fans." Blogging on his website earlier this month, Downing made no mention of any plans to leave the group.